1. Field of the Invention
The present invention relates to a silver halide color photographic light-sensitive material and, more particularly, to a silver halide color photographic light-sensitive material excellent in color reproduction, sharpness, and graininess and improved in deterioration with time in a latent image after exposure and an increase in fog during storage.
2. Description of the Related Art
In recent years, the image qualities of color light-sensitive materials, such as color reproduction, sharpness, and graininess have been significantly advanced. However, there is no end to requirements for the image qualities of light-sensitive materials, so demands have arisen for further progress.
For example, it is known to those skilled in the art that the color reproduction, sharpness, and graininess of a color negative film can be improved by using development inhibitor releasing couplers (so-called DIR couplers), and this technique already has been put into practical use.
The DIR couplers are described in, e.g., JP-A-57-151944 ("JP-A" means Published Unexamined Japanese Patent Application), JP-A-57-154234, JP-A-60-184248, JP-A-60-37346, and U.S. Pat. No. 4,248,962, all described in RD-17643.
The present inventors intended to achieve further improvements in image qualities by using these DIR coupler techniques and have investigated the effect of increasing the use amount of these couplers or production of functional couplers having larger effects.
It was, however, found that a totally unexpected side effect occurred due to these techniques although the image qualities were surely improved; that is, the stability of a latent image after exposure was degraded significantly in light-sensitive materials in which the effects of the development inhibitor releasing compounds were enhanced. Light-sensitive materials for photography are not always developed immediately after photographed but sometimes developed when several months or a year has elapsed after photographed. Therefore, it is desirable that the performance of light-sensitive materials remain unchanged during these periods of storage. The stability of a latent image after exposure includes two conventionally known factors of latent image fading, in which the sensitivity apparently decreases, and latensification, in which it apparently increases. An example of recent studies is described in "The Journal of Photographic Science" by E. F. Thurston, Vol. 38 (pp. 34 to 40, 1990). Latensification is large in light-sensitive materials in which the effects of development inhibitor releasing compounds are enhanced, so light-sensitive materials in which the development inhibiting effect is enhanced to the intended degrees are difficult to put into practical use.
It is also well known to those skilled in the art that, in order to improve the graininess of a light-sensitive material, sensitivity increasing techniques for decreasing the sizes of silver halide grains are important. Recently, to decrease the grain sizes and increase the sensitivities of silver halide grains, the following techniques have been studied and have achieved remarkable results: the improvements in addition timings of sensitizing dyes (e.g., U.S. Pat. Nos. 4,183,756 and 4,225,666, JP-A-58-7,629, JP-A-59-9,658, JP-A-59-48,756, JP-A-59-113,920, JP-A-1-100,533, and JP-A-1-223,411); the use of tabular grains (e.g., U.S. Pat. Nos. 4,434,226, 4,414,310, 4,433,048, 4,414,306, and 4,459,353); and the improvements in reduction-sensitizing methods (e.g., JP-B-57-33572 ("JP-B" means Published Examined Japanese Patent Application), JP-B-58-1410, JP-A-57-82831, JP-A-57-179835, JP-A-2-136852, and EP 0348934). It was, however, found that any of the improvements in addition timings of sensitizing dyes, the increase in amount of sensitizing dyes obtained by the use of tabular grains, and the rise in sensitivity obtained by reduction sensitization was accompanied by degradation in latensification. In addition, it was surprising that the degree of degradation was abnormally large in the abovementioned light-sensitive materials in which the effects of development inhibitor releasing compounds were enhanced.